Telescoping antenna mast



May 26, 1959 E. M. EVANS TELESCORING ANTENNA MAST Filed July 29, 1955III 7""!"1 INVENTOR. 5424 M. EVA/V6 United States Patent TELESCOPIN GANTENNA MAST Earl M. Evans, Crystal River, Fla.

Application July 29, 1955, Serial No. 525,143

6 Claims. (Cl. 189-26) This invention relates to antenna masts, and moreparticularly has reference to a mast of the telescoping type, sodesigned as to be extensible, and subsequently rotatably adjustable, byfluid pressure.

By way of background, certain dificulties arise in connection withconventional telescoping antenna mast constructions. One of thesedifliculties stems from the fact that a conventional mast often isdifiicult to lower once it has been extended and mounted in position,thus making repairs and maintenance diflicult. Further, heretofore, therotatable adjustment of television antennas and the like has beeneffected mainly by electric motor control means, which are somewhatexpensive and are not, at all times, reliable in operation. Further, thetime required in extending or lowering the mast, or in rotatablyadjusting the same, is often excessive in conventional construction, andadditional expense is involved in the fact that heretofore, telescopingmasts have of necessity been, in many instances, of square, triangular,or other non-circular cross section, which construction is moreexpensive than circularly cross sectioned mast structures.

Broadly speaking, the main object'of the present invention is to obviatethe several disadvantages or difliculties which have existed,by'providing a mast when will have none of the undesirable featuresspecified above.

A more specific object is to provide, in a mast construction as stated,means particularly adapted to eifect the extension, retraction, androtation of the mast by means of fluid pressure, such as, for example,that afforded by a city water supply.

Other objects will appear from the following description, the claimsappended thereto, and from the annexed drawing, in which like referencecharacters designate like parts throughout the several views, andwherein:

Figure l is a side elevational view of an antenna mast formed accordingto the present invention, extended for use;

Figure 2 is an enlarged sectional view on line 2-2 of Figure 1; and

Figure 3 is a transverse sectional view on line 3--3 of Figure 2.

The mast constituting the present invention includes a tubular basesection 10, anchored in the ground G, as for example, by being embeddedin concrete. The base section can be embedded in the ground at anydesired depth, or alternatively, can be disposed at or above groundlevel, in which instance it would be mounted on a suitable supportstructure. The manner in which the base section is mounted in avertical, stationary position is not critical to the invention, and itis mainly important that it be stationarily supported, in a strong,secure manner that will assure against its becoming loose or tilting, orbeing pulled completely out of position.

A main extension section 12 is adapted to telescope in the open upperend of the base section 10, said main extension section having a closedbottom provided by an end wall 14. Additional sections can be extendedabove the main extension section 12, as at 16, 18, but again, this isice not critical to the invention, and the section 12 may constitute theonly extension section in the mast.

Loose upon the extension section 12 is a sleeve 20, integrally formedwith 21 depending bell end 22 spaced outwardly from the base section 10,and having threads 24, 26. The thread grooves are of rectangular crosssection, and are extended parallel to one another, with the lower endsof the grooves being disposed degrees apart, and the upper ends of thegrooves also being disposed diametrically opposite one another. Eachgroove extends through 360 degrees within the bell end 22.

Rolling in the respective grooves 24, 26 are fiat, disc shaped rollers28, 30, rotatably mounted upon diametrically opposed pins 32, 34respectively projecting radially, outwardly from the base section 10,through openings formed in the base section adjacent the upper endsthereof. At their inner ends, the pins have flared heads, embedded incorrespondingly flared openings formed in a cylindrical sealing sleeve36 engaged tightly against the inner surface of the base section 10 atthe upper end of the base section.

Threadedly engaged in the upper end portion of sleeve 20 is a set screw38 adapted to bind against the extension section 12.

Guy wires 40, which can be triangularly or otherwise spaced, areanchored at one end to the ground G, and intermediate their ends havesprings 42 to permit extension of the guide wires by resilient stressingof the same. At their upper ends, the wires are secured to eyes carriedby the upper end of the extension section 12.

Communicating with the interior of the base section 10 is a pipe 44through which fluid is adapted to be supplied under pressure, andintermediate the ends of said pipe there is provided a valve 46 which inthe present instance is illustrated as being manually operated. However,the valve can be electrically or otherwise operated, either at thelocation of the base section or from a remote location. A drain tube 48is provided in the pipe 44 at the location of the valve, and if desired,the valve can be a two way valve so as to communicate the base section10 either with a source of fluid under pressure, or with the drain pipe,depending on whether fluid is to be supplied to or drawn from the basesection.

In use, the main extension section 12 would normally be fully telescopedwithin the base section 10, With the sleeve 20 loose upon the extensionsection. Then, the two way valve is operated to close the drain 48 andpermit fluid to be supplied under pressure into the base section. Thefluid under pressure can be gaseous or liquid, whichever is desired, andthe pressure would be such as to cause the extension section 12 to beforced upwardly to the center position thereof shown in Figure 1, or toany other intermediate, selected extended position. 'When the extensionsection has been forced upwardly out of the base section to the desiredextent, the set screw 38 is turned home against the extension section tofixedly connect the sleeve to the extension section. Instead of a setscrew, a split clamp can be employed, or any other means adapted toeffect the quick connection of the sleeve to the extension section,following extension of the section 12 to the desired extent. At thistime, rollers 28, 30 are at the lower extremities of the threads 24, 26.

When the section 12 is forced upwardly out of the base section 10, theguy wires will be drawn taut, and when the sleeve is clamped to theextension section, the extension of the mast will have been completed.

Subsequently, the section 12, and hence the sections 16 and 18 carriedthereby, is rotatably adjustable to any extent, through a full 360degree cycle. This is done by permitting additional fluid to be forcedunder pressure into the base section 10. When this additional fluidunder pressure is supplied to the base section, additional pressure willbe directed against the end Wall 14 of the extension section 12, tendingto force the extension section upwardly. However, sleeve 20 is now fixedto the extension section, and accordingly, the extension section will berotated responsive to the supply of additional fluid pressure to thebase section. As soon as the section 12 has been rotated to its desiredextent, the fluid under pressure is cut ofif.

To rotate the extension section in an opposite direction, fluid isdrained out of the base section it as necessary, and by gravitation,said main extension section 12 will rotate in an opposite direction,until the rollers are again at the lower ends of the thread grooves.Subsequently, if it is desired to lower the extension section, it ismerely necessary to loosen the set screw 33, while permitting the fluidunder pressure to drain out of the base section it), and under thesecircumstances, the extension section 12 will drop down within the basesection, without rotating.

It is believed sufliciently obvious as not to require specialillustration that if desired, the rollers might be mounted on the bellend 22 of sleeve 20, with the thread grooves being formed in the upperend of the base section it), this arrangement being opposite to thatshown in Figure 2. The same results, of course, would be obtained underthese circumstances, and apart from. this reversal of the grooves androllers on the sleeve 20 and base section It), the construction will beidentical to that shown previously herein.

It will be seen that the construction is such as to facilitate theextension or retraction of the antenna mast, and further, theconstruction now permits rotatable adjustment of the antenna mast by thesame fluid pressure which is especially used to extend the mast to thedesired height. Thus, a simpler construction is provided than would berequired under ordinary circumstances, wherein the rotatable adjustmentis effected by an electric motor, while the extension of the mast isei'rected manually or by other means separate from the controls used forrotatable adjustment purposes. Still further, the mast is of circularcross section, thus again reducing the cost, without detraction from itsefiiciency in operation or the speed and ease with which the mast can beextended or retracted.

It is believed apparent that the invention is not nec essarily confinedto the specific use or uses thereof de scribed above, since it may beutilized for any purpose to which it may be suited. Nor is the inventionto be necessarily limited to the specific construction illustrated anddescribed, since such construction is only intended to be illustrativeof the principles, it being considered that the invention comprehendsany minor change in construction that may be permitted within the scopeof the appended claims.

What is claimed is:

1. An extensible mast comprising a hollow base section; means forsupplying fluid under pressure to said base section; an extensionsection telescoped in the base section and constituting a pistonextensible from the base section responsive to the supply of fluid underpressure to the base section; a sleeve slidably mounted upon theextension section and including means for fixedly connecting the sleeveto the extension section in selected positions to which the extensionsection is extended relative to the base section; and a permanentlyengaged threaded connection between the sleeve and base section, foreffecting rotatable adjustment of the extension section responsive tothe supplying of fluid under pressure to the base section with thesleeve secured to the extension section.

2. An extensible mast comprising a hollow base section; means forsupplying fluid under pressure to said base section; an extensionsection telescoped in the base section and constituting a pistonextensible from the base section responsive to the supply of fluid underpressure to the base section; a sleeve slidably mounted upon theextension section and including means for fixedly connecting the sleeveto the extension section in selected positions to which the extensionsection is extended relative to the base section; and a permanentlyengaged threaded connection between the sleeve and base section, foreflecting rotatable adjustment of the extension section responsive tothe supplying of fluid under pressure to the base section with thesleeve secured to the extension section, said threaded connectioncomprising pins projecting radially, outwardly from the base section andthread grooves formed on the sleeve and re ceiving said pins.

3. An extensible mast comprising a hollow base section; means forsupplying fluid under pressure to said base section; an extensionsection telescoped in the base section and constituting a pistonextensible from the base section responsive to the supplying fluid underpressure to the base section; a sleeve slidably mounted upon theextension section and including means for fixedly connecting the sleeveto the extension section in selected positions to which the extensionsection is extended relative to the base section; and a permanentlyengaged threaded connection between the sleeve and base section, foreffecting rotatable adjustment of the extension section responsive tothe supplying of fluid under pressure to the base section with thesleeve secured to the extension section, said threaded connectionscomprising pins projecting radially, outwardly from the base section,rollers on the outer ends of the pins, and thread grooves formed on theinner surface of the sleeve and receiving said rollers.

4. An extensible mast comprising a hollow base section; means forsupplying fluid under pressure to said base section; an extensionsection telescoped in the base section and constituting a pistonextensible from the base section responsive to the supply of fluid underpressure to the base section; a sleeve slidably mounted upon theextension section and including means for fixedly connecting the sleeveto the extension section in selected positions to which the extensionsection is extended relative to the base section; and a permanentlyengaged threaded connection between the sleeve and base section, foreffecting rotatable adjustment of the extension section responsive tothe supplying of fluid under pressure to the base section with thesleeve secured to the extension section, said threaded connectionscomprising pins projecting radially, outwardly from the base section,said pins being permanently engaged in the base section againstretraction in a radial direction from their outwardly projectingpositions, rollers on the outer ends of the pins, and thread groovesformed on the inner surface of the sleeve and receiving said rollers,there being a pair of said pins and a pair of grooves receiving thepins, the grooves having their upper and lower ends diametricallyopposed, said pins being diametrically opposed correspondingly to thegrooves for disposition of a roller in each of the grooves.

5. An extensible antenna mast comprising a tubular base section ofcircular cross section adapted to be embedded in a stationary positionin a support, said base section being formed open at its upper end; anextension section of circular cross section telescoping Within the openupper end of the base section, said extension section being closed atits lower end to form the same as a piston; means for supplying fluidunder pressure to the base section below the closed lower end of theextension section, thus to, in response to the supplying of fluid underpressure to the base section, extend the extension section out of thebase section to a predetermined extent; sealing means interposed betweenthe base and extension sections; a sleeve loose upon the extensionsection and formed with a depending, bell end receiving the upper end ofthe base section, said bell end of the sleeve having internal,diametrically opposed thread grooves; means for fixedly securing thesleeve to the extension section is selected positions to which theextension section is forced outwardly from the base sections; and a pairof diametrically opposed, radially, outwardly projecting pins carried bythe base section adjacent the open upper end thereof, said pins beingpermanently engaged in the base section against retraction in a radialdirection from their outwardly projecting positions, said pins includingrollers at their outer ends engaging in the respective grooves, thus toeflect rotatable adjustment of the extension section with the sleevefixedly secured thereto, responsive to the supplying of fluid underpressure to the base section, said extension sec tion being extendablewithout rotation of the same responsive to the supplying of fluidpressure to the base section, when said sleeve is loose upon theextension section.

6. A telescoping antenna mast comprising a hollow, upright, upwardlyopening, stationary, cylindrical base section, an upright, elongatedextension section slidably telescoped at its lower end in the basesection; means communicating with the base section through which fluidun der pressure may be directed, for forcing the extension sectionupwardly within the base section; a sleeve circumposed about theextension section at one end of the sleeve and about the base section atthe other end of the sleeve, the sleeve being rotatable relative to boththe extension section and the base section, the extension section beinglongitudinally slidable in the sleeve; a threaded connection between thebase section and the sleeve; means on the sleeve for releasablyconnecting the same fixedly to the extension section in any position towhich the extension section is telescopically adjusted relative to thebase section, whereby to conjointly rotate the sleeve and extensionsection responsive to direction of fluid under pressure to the basesection in any position of telescopic adjustment of the extensionsection with the sleeve and extension section fixedly connected, whileproviding for movement of the extension section longitudinally of thebase section without being rotated whenever fluid under pressure issupplied to the base section while the sleeve and extension section arenot fixedly connected; and means on the extension section for supportingan antenna.

References Cited in the file of this patent UNITED STATES PATENTS322,679 Campbell July 21, 1885 2,144,447 Barnhart Ian. 17, 19392,219,844 Lotter et al. Oct. 29, 1940 2,708,493 Badertscher et a1 May17, 1955 2,791,909 Rick May 14, 1957

